Overview of TLRs-TLR ligands and their signaling complexes in normal and malignant human B cells. TLR2 associates with TLR6 or TLR1 to form receptors that recognize diacylated and triacylated lipopeptides, respectively. TLR3 recognizes virally derived dsRNA. TLR4 recognizes LPS from Gram-negative bacteria, and several putative endogenous ligands. TLR5 recognizes bacterial flagellin. TLR7 and TLR8 recognize ssRNA from viruses, imidazoquinolines, and nucleoside analogs. TLR9 recognizes CpG DNA from bacteria and viruses, immunoglobulin-DNA complexes, and HMGB1. Unlike TLR1, 2, 5, 6, 7/8, and 9, which are expressed by normal and malignant human B cells, TLR3 and TLR4 are expressed solely by malignant B cells and are shown hatched. A total of 4 signaling adaptors are involved in TLR signaling: MyD88, TRIF, TRAM, and TIRAP. TLR signaling pathways result in the production of IL-6, IL-10, and type I IFN.